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Finding the Fourth Proportional to 405.21, 607.88 and 131.28

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Solution

The fourth proportional to 405.21, 607.88 and 131.28 is: 196.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.21 : 607.88 = 131.28 : x
  2. Step 2: Convert to fraction form
    405.21/607.88 = 131.28/x
  3. Step 3: Cross multiply
    405.21x = 607.88 × 131.28
  4. Step 4: Simplify right side
    405.21x = 79,802.49
  5. Step 5: Solve for x
    x = 79,802.49/405.21
  6. Step 6: Final answer
    x = 196.94

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.